Patent FR-A-2,720,488 describes a device intended for heat exchange and cleaning of polluted gases such as VOC by thermal and/or catalytic effect. It comprises a housing or cage, a pipe for feeding polluted effluents into the cage, another pipe for discharging the processed effluents from the cage, a ring containing an inert charge of solid particulate materials exhibiting a large heat exchange surface (silica, granite or lighter materials such as metal honeycomb structures or others, or cryogenic nodules for negative temperatures, etc.) which is arranged within the cage. The ring can be divided into several parts by means of an inner partitioning or, in some cases, serve as a support for a certain number of baskets. Motive means are used to drive the ring and the cage into a rotating motion with respect to each other around a vertical axis (either the ring rotates, the cage being stationary, or the ring is stationary and the cage rotates around it). A first heat transfer occurs between the effluents and the inert charge in a first angular sector of the ring. A second heat transfer occurs between effluents and the charge in the ring in a second sector of the ring. A thermal reactor possibly provided with a catalyst bed is arranged in this central part in order to burn the polluting substances in the effluents channelled by the first angular area.
Patent FR-A-2,728,483 describes a device intended for catalytic cleaning of effluents polluted by VOC comprising, within a stationary cage, a rotating ring of vertical axis comprising an annular catalyst bed covering the inner wall thereof and an annular charge, outside the catalyst bed, of a material exhibiting a large heat exchange surface. The effluents flow twice through the catalyst bed on either side of the central zone. A burner is placed above the central reaction zone and it is connected to a fuel injection pipe by means of a rotary joint. It is used to heat the incoming effluents so as to reach an autothermal working point, or possibly to provide makeup heat in cases where the polluting VOC compound content is insufficient to reach it.